The present invention relates to a storage device, and is suitable for application to for example a semiconductor storage device that stores data supplied from an information processing apparatus such as a personal computer, a digital camera or the like in an internal semiconductor memory.
A conventional semiconductor storage device of this type, being connected to an information processing apparatus corresponding to a personal computer, a digital camera or the like, performs a data writing process for writing data supplied from the information processing apparatus to an internal semiconductor memory and a data reading process for reading data requested by the information processing apparatus from the internal semiconductor memory, using power supplied from the information processing apparatus (see U.S. Pat. No. 6,148,354 as Patent Document 1, for example).
When the information processing apparatus to which such a semiconductor storage device is connected corresponds to a digital camera operating on power supplied from a battery provided within the information processing apparatus, for example, an effect of reducing the power consumption of the digital camera and the like can be obtained when the data write processing speed and the data read processing speed of the semiconductor storage device can be decreased to a certain extent.
When the information processing apparatus to which such a semiconductor storage device is connected corresponds to a personal computer operating on power supplied from a commercial power supply within a house, for example, an effect of shortening the processing time of data write processing and data read processing and the like can be obtained when the data write processing speed and the data read processing speed of the semiconductor storage device can be increased.
It is considered that convenience can be greatly improved when the data write processing speed and the data read processing speed of the semiconductor storage device can be thus changed according to a situation in which the semiconductor storage device is used.
Further, when such a semiconductor storage device can guarantee a minimum data write processing speed and a minimum data read processing speed according to a kind of data (moving image data or musical (audio) data) to be read and written, the semiconductor storage device can for example record moving image data without dropping frames and record/reproduce musical (audio) data seamlessly.
The present invention has been made in view of the above points. It is desirable to propose a storage device that can appropriately change data write processing speed and data read processing speed and a storage device that can guarantee a data write processing speed and a data read processing speed.